August 4

1578 - Battle of Al Kasr al Kebir - Moroccans defeat Portuguese. King Sebastian of Portugal is defeated and killed in North Africa, leaving his elderly uncle, Cardinal Henry, as his heir. This initiates a succession crisis in Portugal.

1969 - Vietnam War: At the apartment of French intermediary Jean Sainteny in Paris, US representative Henry Kissinger and North Vietnamese representative Xuan Thuy begin secret peace negotiations. The negotiations will eventually fail.